Such devices are previously known, the screening means being intended to take an active position against the bucket itself, when a fine fraction of the material in the bucket shall be emptied out of this one, and an inactive position swung out from the bucket when a coarse fraction of the material shall be emptied out of the bucket.
The problem with known screening devices is that the screening means itself has a complicated fastening on the bucket, which means that the mounting and the demounting work, respectively, of the screening means onto respectively from the bucket itself becomes very extensive. This has the consequence that the owner of the digging machine as a rule must have a special bucket for a certain type of work and a combined aggregate comprising a bucket and a screening device for another type of work.